...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Atmospheric environment >Atmospheric aerosol over two urban-rural pairs in the southeastern United States: Chemical composition and possible sources
【24h】

Atmospheric aerosol over two urban-rural pairs in the southeastern United States: Chemical composition and possible sources

机译：美国东南部两个城乡对的大气气溶胶：化学成分和可能的来源

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Positive matrix factorization (PMF) was used to infer the sources of PM_(2.5) observed at four sites in Georgia and Alabama. One pair of urban and rural sites in each state is used to examine the regional and urban influence on PM_(2.5) concentrations in the Southeast. Eight factors were resolved for the two urban sites and seven factors were resolved for the two rural sites. Spatial correlations of factors were investigated using the square of correlation coefficient (R~2) calculated from the resolved G factors. Fourier transform was used to define the temporal characteristics of PM_(2.5) factors at these sites. Factors were normalized by using aerosol fine mass concentration data through multiple linear regression to obtain the quantitative factor contributions for each resolved factor. Common factors include: (1) secondary sulfate dominated by high concentrations of sulfate and ammonium with a strong seasonal variation peaking in summer; (2) nitrate and the associated ammonium with a seasonal maximum in winter; (3) "coal combustion/other" factor with presence of sulfate, EC, OC, and Se; (4) soil represented by Al, Ca, Fe, K, Si and Ti; and (5) wood smoke with the high concentrations of EC, OC and K. The motor vehicle factor with high concentrations of EC and OC and the presence of some soil dust components is found at the urban sites, but cannot be resolved for the two rural sites. Among the other factors, two similar industry factors are found at the two sites in each state. For the wood smoke factor, different seasonal trends are found between urban and rural sites, suggesting different wood burning patterns between urban and rural regions. For the industry factors, different seasonal variations are also found between urban and rural sites, suggesting that this factor may come from different sources or a common source may impact the two sites differently. Generally, sulfate, soil, and nitrate factors at the four sites showed similar chemical composition profiles and seasonal variation patterns reflecting the regional characteristics of these factors. These regional factors have predominantly low frequency variations while local factors such as coal combustion, motor vehicle, wood smoke, and industry factors have high frequency variations in addition to low frequency variations.
机译：正矩阵分解（PMF）用于推断在佐治亚州和阿拉巴马州四个地点观测到的PM_（2.5）的来源。每个州使用一对城乡站点来研究东南部区域和城市对PM_（2.5）浓度的影响。解决了两个城市地点的八个因素，解决了两个农村地点的七个因素。使用从解析的G因子计算出的相关系数的平方（R〜2）来调查因子的空间相关性。使用傅立叶变换来定义这些位置的PM_（2.5）因子的时间特征。通过多元线性回归使用气溶胶精细质量浓度数据对因子进行归一化，以获得每个分解因子的定量因子贡献。常见因素包括：（1）次级硫酸盐以高浓度的硫酸盐和铵盐为主，夏季出现强烈的季节性变化； （2）硝酸盐及相关的铵盐在冬季为季节性最高； （3）存在硫酸盐，EC，OC和Se的“煤燃烧/其他”因素； （4）以铝，钙，铁，钾，硅和钛为代表的土壤； （5）高浓度EC，OC和K的木烟。高浓度EC和OC的机动车因子以及一些土壤粉尘成分存在于城市现场，但是这两种方法无法解决农村遗址。在其他因素中，每个州的两个站点都发现了两个类似的行业因素。对于木材烟雾因子，城乡之间发现了不同的季节性趋势，表明城乡之间的木材燃烧方式不同。对于行业因素，城乡站点之间还发现了不同的季节性变化，这表明该因素可能来自不同的来源，或者一个共同的来源可能对这两个站点产生不同的影响。通常，四个地点的硫酸盐，土壤和硝酸盐因子显示出相似的化学组成特征和季节性变化模式，反映了这些因子的区域特征。这些区域因素主要是低频变化，而局部因素（例如煤燃烧，机动车，木材烟雾和工业因素）除了低频变化外，还有高频变化。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号